Log Cabin Restoration

Because it is part of the history of our high altitude Colorado ranch, my husband wants to restore an old coal miner's cabin. It is small, 15' x 20'-ish and most of the logs are in good condition, with the exception of the bottom row, which are rotted out from being laid close to the ground and with just sandstone rocks at the corners for the "foundation." It is actually amazing that they've held up for almost a century.

Wanting to raise it off the ground and put a proper foundation under it.

But the old wood floor is attached to these crappy bottom logs. A wooden ledge was created on the logs to support the floor boards. We'd hoped to retain the old floor boards in place to use as the subfloor and then place new wood boards on top. But that seems impossible now that we see how the floor was built onto the first row of logs.

And will it be possible to jack up the little cabin, given the bad logs on the bottom? Where/how to jack? Is there a way to jack it from above the first layer of logs? Or maybe we could remove only the portions of the first row that are bad (the corners, mainly) and just replace sections of them...but can it be done piecemeal like that?

Is it possible to do this renovation work with the cabin intact or will we be better off dismantling and rebuilding entirely? We'd like to have a simple "fix" rather than a huge project, given that this will just be a little guest cabin in the end.

I'd have to see it, start jacking may make it worse in other areas. Rebuild who knows what can be salvaged. I guess you are saying the floor joist are resting on a rim joist attached to a lower rotted wall log? A pic would help here.

IMO your best shot is probably to remove those ties (floor joist-to-rotted lower logs). Poor piers that are restricted by the depth of a new sill beam you find in international code tables or online look for spans of 2x8's, 2x10's, 4x4's, 4x6s, it's 12-16'_ or more depending on species, or what ever depth the floor plane will allow below it. Set the concrete piers at least 1' in diameter to frost depth. Embed some concrete steel anchor metal sill beam connectors. You now have a lower sill like the old rim joist functioned to set the old floor joist on and AND cantilever this out to support the walls no more than 12"....double this cantilever. Reset good lower log/sills for the rest of the wall to sit on. Do a lower wall R&R little at a time setting the logs on the new lower sill lower cantilevered out that is supported by concrete piers. Does that make sense?

Quite a bit work let you decide if it's worth it. Excuse the crude drawing I did it in 3 mins.

That's a really fun video of the building of a new lean-to. For restoring your old one given the way it is supported, I think your best bet might be to sacrifice the original bottom logs, probably carefully remove the interior floorboards and whatever else is there, and raise the cabin using the sound second logs. The original foundation held for a century, I see no reason a similar one couldn't hold up for another century. I would get four additional stone blocks to either put on top of the originals or under them, depending on circumstances (if the originals are not wide enough to be stable with added stones on top, raise them and use wider ones underneath). If you can find something less permeable than sandstone, that would probably help, otherwise, simply having a stone that is not in direct contact with the earth supporting the logs would reduce wicking. Flashing between stones and logs might be a big help, if so, I would use copper which will last effectively forever in most conditions. Insert new bottom logs cut to match the original as much as possible with the support ledge cut in, lower the rest of the cabin onto the new base, and replace the floorboards and whatever other structure there is.

Maria Brown

Posts: 15

1

posted 1 year ago

Thanks for the ideas and tips. I'll get some pics up as we go along. Here's a starter one...we have lived in this cabin (2 adults, 1 very active son and 3 and then 4 dogs...) for a number of years while building our larger log home.

K-S-old-cabin.jpeg

Glenn Herbert

gardener

Posts: 2484

Location: Upstate NY, zone 5

86

posted 1 year ago

Very nice! I would want renovations to that structure to follow original materials and methods as closely as practical.

Maria Brown

Posts: 15

1

posted 1 year ago

Yep, we've got some logs we salvaged from an old building tear-down that match these very well ~ milled flat on 3 sides, outer surface being round.

We keep debating whether to change the pitch of the roof, though. As it is, it is shallow and doesn't shed snow. We've had up to 6' of snow sitting on top till spring melt. I keep voting for enough of an angle to the roof to allow for a little loft up in the rafters. But that, of course, will depart from the frumpy little coal miner's cabin look.